Make polls for removing mesh data layers consistent

This was reported in T90026 for attributes, but was also true for:
- UVMaps
- Vertex Colors
- Sculpt Vertex Colors
- Face Maps

For Vertex groups and Shapekeys this was already done (in that their
remove poll would check if there is a vertex group or shapekey to begin
with), now make this consistent across all mentioned types.

Thx @vvv for the initial patch (where this was done for attributes only)

ref T90026

Reviewed By: HooglyBoogly

Maniphest Tasks: T90026

Differential Revision: https://developer.blender.org/D11990

1 files changed, 16 insertions, 1 deletions

diff --git a/source/blender/editors/object/object_facemap_ops.c b/source/blender/editors/object/object_facemap_ops.c
index 3d4d3c8f622..92f3d28878c 100644
--- a/source/blender/editors/object/object_facemap_ops.c
+++ b/source/blender/editors/object/object_facemap_ops.c
@@ -176,6 +176,21 @@ static bool face_map_supported_edit_mode_poll(bContext *C)
   return false;
 }
 
+static bool face_map_supported_remove_poll(bContext *C)
+{
+  if (!face_map_supported_poll(C)) {
+    return false;
+  }
+
+  Object *ob = ED_object_context(C);
+  bFaceMap *fmap = BLI_findlink(&ob->fmaps, ob->actfmap - 1);
+  if (fmap) {
+    return true;
+  }
+
+  return false;
+}
+
 static int face_map_add_exec(bContext *C, wmOperator *UNUSED(op))
 {
   Object *ob = ED_object_context(C);
@@ -225,7 +240,7 @@ void OBJECT_OT_face_map_remove(struct wmOperatorType *ot)
   ot->description = "Remove a face map from the active object";
 
   /* api callbacks */
-  ot->poll = face_map_supported_poll;
+  ot->poll = face_map_supported_remove_poll;
   ot->exec = face_map_remove_exec;
 
   /* flags */